To celebrate the holiday season this year we’ll take a look at Christmas Trees, whose “leaves are so unchanging. Not only green when summer’s here, but also when ’tis cold and drear”1. In the United States, an estimated 31 million Christmas trees are sold each year, with over 7 million of those being grown in the north-western state of Oregon, where large areas of land are dotted with carefully planted rows of trees in various stages of growth. Each tree has to be carefully trimmed each year to ensure that it grows into the perfect conical shape. Holiday…